For example, Japanese Unexamined Patent Publication H11-8742 (FIG. 2) discloses a sensing apparatus that utilizes a mirror array, as an image sensing apparatus that senses image information.
In addition, Japanese Unexamined Patent Publication 2003-331267 (see FIG. 2) discloses an image sensing device having a telecentric optical system and an illumination system that are suited to test on one-time primary scanning of a plurality of testing portions being present on a mounting substrate.
Furthermore, Japanese Unexamined Patent Publication H5-328024 discloses that an image sensing apparatus includes a light source lamp 24 that shines light beams on a sensing object G; optical means 20 and 30 for transmitting light beams reflected by the sensing object G; an optical element 44 for dividing the light beams from the optical means 20 and 30, into a plurality of light fluxes each spaced apart a predetermined distance; and a plurality of detectors 46r, 46g and 46b provided with different color filters, at a position where each of the light beams divided by the optical element 44 is received.
In the image sensing apparatus as set forth in Japanese Unexamined Patent Publication H11-8742, the mirror array in an optical path from a document 10 to a photo-sensor array 15 is configured to determine inclination of the optical axis of a first and a second mirror array so that an axis perpendicular to the sensing surface of a document sensing section may be in parallel with an axis perpendicular to a light-receiving surface of the photosensor array; however, no detailed description is disclosed regarding the mirror array's specific location and the optical axis inclination.
The image sensing apparatus as set forth in Japanese Unexamined Patent Publication 2003-331267, including an epi-illumination light source 1 and a side-illumination light source 4, are constituted by a first lens 9 composed of a cylindrical lens and a second lens 7 of the image-taking system; and the first lens 9 is located within 50 mm apart from the test substrate, and the posterior focal point of the first lens 9 is made to coincide with the incident pupil position of the second lens 7, thereby achieving a compact and telecentric optical system; however, no detailed description is disclosed regarding their specific locations and a scan method.
Furthermore, a problem has been that in the apparatus as disclosed in Japanese Unexamined Patent Publication H5-328024, there is a need for a focusing optical element 42 that makes variable a focusing distance for converting red-blue-green (RGB) image information into electrical signals using a three-line CCD (charge-coupled device) sensor array 46, thus resulting in a complex configuration.
The present invention is directed to overcome the foregoing issues, and an object of the present invention is to provide an image sensing apparatus having a large depth of focus and being compact in size.